This invention relates generally to ovens with visible light cooking elements and, more particularly, to a combination oven using both radiant and microwave energy.
Ovens using visible light cooking elements, i.e., radiant cooking lamps, energize one or more visible light cooking elements according to pre-selected control algorithms to deliver a sufficient amount of energy to cook selected food. However, on occasion an oven cavity is preheated from prior cooking. When the temperature of the oven cavity reaches a certain threshold, latent heat in the oven cavity imparts additional energy to the food. When thermal energy from the pre-heated oven cavity is combined with the radiant energy of the lamps, food can be overcooked.
Another type of oven includes both radiant cooking elements and a magnetron, or microwave, cooking element. The cooking elements and magnetron are controlled to provide reduced cooking time as compared to known radiant ovens, yet a wide variety of foods can be cooked in such ovens. One such combination oven is operable in a speed cooking mode wherein both radiant and microwave cooking elements are utilized, in a microwave only cooking mode wherein only the magnetron is utilized for cooking, and a radiant only cooking mode wherein only the lamps are utilized for cooking. In such an oven, while the magnetron cooking is generally unaffected by temperature conditions of the oven cavity prior to cooking, thermal energy in the oven cavity prior to cooking can negatively affect the radiant cooking cycles and overcook the food.
Compensation for thermal variation of the oven cavity must be provided in order to provide acceptable cooking results.